Logistic regression analysis confirmed IL-40 as an independent predictor in the newly diagnosed (OR = 1.023, 95% CI: 1.010–1.035, p = 0.002) and RA MTX-treated patients (OR = 1.023, 95% CI: 1.011–1.036, p < 0.001). Here, C17orf99 is linked to rheumatoid arthritis.